:root {
  --bg: #ffffff;
  --ink: #0d1b2a;
  --ink-soft: #3d4a5c;
  --ink-faint: #6b7a8c;
  --rule: #dde4ec;
  --rule-soft: #eef2f6;
  --blue: #1e4d8c;
  --blue-deep: #122e54;
  --blue-bright: #2d6cb7;
  --blue-pale: #eef4fb;
  --accent: #c8941a;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--ink);
  font-family: 'Source Sans 3', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: var(--blue-bright);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s, color 0.15s;
}
a:hover { color: var(--blue); border-bottom-color: var(--blue-bright); }

/* ==================== TOP BAR ==================== */
.topbar {
  background: var(--blue-deep);
  color: rgba(255,255,255,0.8);
  font-size: 12px;
  padding: 8px 0;
}
.topbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  justify-content: space-between;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.04em;
}
.topbar-inner a { color: rgba(255,255,255,0.85); border: none; }
.topbar-inner a:hover { color: white; }

/* ==================== MASTHEAD ==================== */
header.masthead {
  border-bottom: 3px solid var(--blue);
  background: white;
  position: relative;
}
.masthead::after {
  content: "";
  position: absolute;
  bottom: -7px;
  left: 0; right: 0;
  height: 1px;
  background: var(--blue);
  opacity: 0.3;
}

.masthead-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 24px 32px 22px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo-mark {
  width: 80px;
  height: 80px;
  flex-shrink: 0;
}

.qw-logo-link {
  display: block;
  flex-shrink: 0;
  border: none;
  transition: all 0.3s ease;
}
.qw-logo-link:hover { border: none; }
.qw-logo-link:hover .qw-logo {
  filter: drop-shadow(0 0 5px rgba(125, 46, 124, 0.5));
  transform: scale(1.02);
}
.qw-logo {
  width: 84px;
  height: 84px;
  display: block;
  object-fit: contain;
  filter: drop-shadow(0 0 3px rgba(125, 46, 124, 0.35));
  transition: all 0.3s ease;
}

/* Quantum tunneling decorative bridge from logo to center */
.tunneling-bridge { display: none; }

.brand-text {
  flex-shrink: 0;
  min-width: 0;
  position: relative;
  z-index: 2;
}

.brand-title {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 46px;
  font-weight: 600;
  color: var(--blue-deep);
  letter-spacing: -0.02em;
  line-height: 1;
}
.brand-title .si { color: var(--blue-bright); font-style: italic; }
.brand-title .slash { color: var(--rule); font-weight: 400; margin: 0 6px; }
.brand-title .stable { color: var(--ink-soft); font-weight: 500; font-style: italic; }
.brand-title sup {
  font-size: 14px;
  font-weight: 500;
  color: var(--accent);
  margin-left: 6px;
  font-style: normal;
  vertical-align: super;
  font-family: 'JetBrains Mono', monospace;
}

.brand-tagline {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 17px;
  font-style: italic;
  color: var(--ink-soft);
  margin-top: 10px;
  font-weight: 400;
}

.masthead-right {
  text-align: right;
  font-size: 13px;
  line-height: 1.4;
  color: var(--ink-soft);
  border-left: 1px solid var(--rule);
  padding-left: 28px;
  flex-shrink: 0;
}
.masthead-right .date {
  font-family: 'Source Serif 4', serif;
  font-weight: 600;
  font-size: 16px;
  color: var(--blue-deep);
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}
.masthead-right .venue { font-style: italic; }
.masthead-right .colocate {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-top: 6px;
}

/* ==================== NAV ==================== */
nav.primary {
  background: white;
  border-bottom: 1px solid var(--rule);
}
.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  gap: 4px;
  justify-content: space-between;
  align-items: center;
}
.nav-tabs { display: flex; gap: 4px; }
.nav-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-family: 'Source Sans 3', sans-serif;
  font-size: 14px;
  font-weight: 500;
  color: var(--ink-soft);
  padding: 14px 22px;
  position: relative;
  transition: color 0.15s, background 0.15s;
  letter-spacing: 0.01em;
}
.nav-btn:hover { color: var(--blue); background: var(--blue-pale); }
.nav-btn.active {
  color: var(--blue);
  font-weight: 600;
}
.nav-btn.active::after {
  content: "";
  position: absolute;
  left: 0; right: 0;
  bottom: -1px;
  height: 3px;
  background: var(--blue-bright);
}

/* ==================== ANNOUNCEMENT BAR ==================== */
.announce {
  background: var(--blue-pale);
  border-bottom: 1px solid var(--rule);
  padding: 12px 0;
  font-size: 14px;
}
.announce-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: flex;
  align-items: center;
  gap: 14px;
}
.announce-badge {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: white;
  background: var(--blue);
  padding: 3px 8px;
  border-radius: 2px;
}
.announce-text { color: var(--ink); }
.announce-text strong { color: var(--blue-deep); font-weight: 600; }

/* ==================== MAIN CONTAINER ==================== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 32px 80px;
}

.page { display: none; animation: fadeIn 0.3s ease; }
.page.active { display: block; }
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==================== PAGE HEADERS ==================== */
.page-header {
  margin-bottom: 40px;
  padding-bottom: 20px;
  border-bottom: 2px solid var(--blue);
}
.page-eyebrow {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--blue-bright);
  margin-bottom: 10px;
  font-weight: 500;
}
.page-title {
  font-family: 'Source Serif 4', Georgia, serif;
  font-size: 42px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.1;
  color: var(--blue-deep);
}
.page-title em { color: var(--blue-bright); font-weight: 500; }
.page-subtitle {
  margin-top: 12px;
  font-size: 18px;
  color: var(--ink-soft);
  line-height: 1.45;
  max-width: 800px;
}

h2.subhead {
  font-family: 'Source Serif 4', serif;
  font-size: 22px;
  font-weight: 600;
  color: var(--blue-deep);
  margin: 44px 0 16px;
  padding-bottom: 6px;
  border-bottom: 1px solid var(--rule);
  letter-spacing: -0.01em;
}
h2.subhead:first-child { margin-top: 0; }

.prose p {
  margin-bottom: 16px;
  font-size: 16px;
  line-height: 1.7;
  max-width: 72ch;
}
.prose p:last-child { margin-bottom: 0; }

/* ==================== HOME / ABOUT ==================== */
.hero-card {
  background: white;
  border: 1px solid var(--rule);
  border-left: 4px solid var(--blue-bright);
  padding: 24px 28px;
  margin-bottom: 36px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 28px;
}
.hero-card .field .label {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-faint);
  margin-bottom: 6px;
  font-weight: 500;
}
.hero-card .field .value {
  font-size: 15px;
  line-height: 1.35;
  color: var(--ink);
}
.hero-card .field .value strong {
  font-weight: 600;
  color: var(--blue-deep);
  display: block;
  font-size: 16px;
}

.about-layout {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 48px;
  align-items: start;
}

.sidecard {
  background: var(--rule-soft);
  border: 1px solid var(--rule);
  padding: 22px 24px;
}
.sidecard h4 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue);
  font-weight: 500;
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}
.sidecard p {
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
  margin-bottom: 10px;
}
.sidecard p:last-child { margin-bottom: 0; }
.sidecard a { font-weight: 500; }

.topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 40px;
}
.topic-item {
  padding: 13px 0;
  border-bottom: 1px solid var(--rule-soft);
  display: flex;
  gap: 14px;
  align-items: baseline;
  font-size: 15px;
  line-height: 1.45;
}
.topic-item .marker {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  color: var(--blue-bright);
  width: 28px;
  flex-shrink: 0;
  font-weight: 500;
}

/* Banner with cross-layer diagram */
.banner-img {
  width: 100%;
  height: 240px;
  margin: 32px 0;
  background: linear-gradient(135deg, var(--blue-deep) 0%, var(--blue) 60%, var(--blue-bright) 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}
.banner-img svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.banner-img .caption {
  position: relative;
  text-align: center;
  font-family: 'Source Serif 4', serif;
  font-style: italic;
  font-size: 22px;
  font-weight: 400;
  letter-spacing: 0.01em;
  z-index: 2;
  padding: 0 24px;
}
.banner-img .caption .place {
  display: block;
  font-style: normal;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  margin-top: 12px;
  opacity: 0.85;
}

/* Stack diagram */
.stack-diagram {
  margin: 32px 0;
  border: 1px solid var(--rule);
  background: white;
}
.stack-layer {
  display: grid;
  grid-template-columns: 180px 1fr;
  border-bottom: 1px solid var(--rule);
  align-items: center;
}
.stack-layer:last-child { border-bottom: none; }
.stack-layer .layer-name {
  background: var(--blue-pale);
  padding: 18px 20px;
  border-right: 3px solid var(--blue-bright);
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--blue-deep);
  font-weight: 600;
  height: 100%;
  display: flex;
  align-items: center;
}
.stack-layer .layer-desc {
  padding: 16px 22px;
  font-size: 14px;
  line-height: 1.55;
  color: var(--ink-soft);
}
.stack-layer .layer-desc strong { color: var(--blue-deep); font-weight: 600; }

/* ==================== CFP ==================== */
.callout {
  background: var(--blue-pale);
  border-left: 4px solid var(--blue-bright);
  padding: 18px 24px;
  margin: 24px 0 32px;
}
.callout p { font-size: 15px; line-height: 1.6; }
.callout p + p { margin-top: 8px; }
.callout strong { color: var(--blue-deep); font-weight: 600; }

.cfp-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
}

.dates-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
}
.dates-table td {
  padding: 11px 0;
  border-bottom: 1px solid var(--rule-soft);
  vertical-align: baseline;
}
.dates-table td:first-child { color: var(--ink); }
.dates-table td:last-child {
  text-align: right;
  font-family: 'JetBrains Mono', monospace;
  font-size: 13px;
  color: var(--ink-soft);
  white-space: nowrap;
}
.dates-table tr.urgent td { font-weight: 600; }
.dates-table tr.urgent td:last-child { color: var(--blue-bright); }
.dates-table tr.tbd td:last-child { color: var(--ink-faint); font-style: italic; }

.submit-btn {
  display: inline-block;
  margin-top: 28px;
  padding: 12px 28px;
  background: var(--blue);
  color: white;
  border: 1px solid var(--blue);
  font-family: 'Source Sans 3', sans-serif;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border-bottom: 1px solid var(--blue);
  transition: background 0.2s;
}
.submit-btn:hover {
  background: var(--blue-deep);
  border-color: var(--blue-deep);
  color: white;
  border-bottom-color: var(--blue-deep);
}

.review-criteria {
  font-size: 15px;
  line-height: 1.75;
  padding-left: 22px;
}
.review-criteria li { padding: 4px 0; }
.review-criteria li::marker { color: var(--blue-bright); font-weight: 600; }

/* ==================== PROGRAM ==================== */
.session-block {
  margin-bottom: 22px;
  border: 1px solid var(--rule);
  background: white;
}
.session-header {
  background: var(--blue-deep);
  color: white;
  padding: 14px 22px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
}
.session-header .session-num {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  opacity: 0.7;
  margin-right: 8px;
}
.session-header .session-name {
  font-family: 'Source Serif 4', serif;
  font-size: 17px;
  font-weight: 600;
  flex-grow: 1;
}
.session-header .session-time {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  opacity: 0.85;
  white-space: nowrap;
}
.session-body {
  padding: 16px 22px;
  font-size: 15px;
  line-height: 1.6;
  color: var(--ink-soft);
}
.session-body strong { color: var(--ink); font-weight: 600; }

.standalone-item {
  padding: 14px 22px;
  border: 1px solid var(--rule);
  background: var(--rule-soft);
  margin-bottom: 22px;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
}
.standalone-item .name {
  font-family: 'Source Serif 4', serif;
  font-weight: 600;
  font-size: 16px;
  color: var(--blue-deep);
}
.standalone-item .time {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--ink-faint);
  text-transform: uppercase;
}

/* ==================== COMMITTEE ==================== */
.pc-group { margin-bottom: 36px; }

.pc-card-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.pc-card-grid.cols-2 { grid-template-columns: repeat(2, 1fr); }

.pc-card {
  border: 1px solid var(--rule);
  padding: 18px 20px;
  background: white;
  transition: border-color 0.2s, box-shadow 0.2s;
}
.pc-card:hover { border-color: var(--blue-bright); box-shadow: 0 2px 8px rgba(30, 77, 140, 0.06); }
.pc-card .name {
  font-family: 'Source Serif 4', serif;
  font-weight: 600;
  font-size: 17px;
  color: var(--blue-deep);
  line-height: 1.25;
  margin-bottom: 4px;
}
.pc-card .role {
  font-family: 'JetBrains Mono', monospace;
  font-size: 9px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--blue-bright);
  margin-bottom: 8px;
  font-weight: 500;
}
.pc-card .aff {
  font-size: 14px;
  color: var(--ink-soft);
  line-height: 1.4;
  margin-bottom: 8px;
}
.pc-card .aff em { font-style: italic; }
.pc-card .contact a {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  word-break: break-all;
}

.pc-list-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0 32px;
}
.pc-list-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--rule-soft);
  display: flex;
  flex-direction: column;
  gap: 2px;
}
.pc-list-item .name { font-weight: 600; color: var(--ink); font-size: 15px; }
.pc-list-item .aff { font-size: 13px; color: var(--ink-faint); font-style: italic; }

/* ==================== ATTEND ==================== */
.attend-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: 40px;
  margin-top: 28px;
}
.attend-detail {
  width: 100%;
  border-collapse: collapse;
  font-size: 15px;
}
.attend-detail td {
  padding: 11px 0;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}
.attend-detail td:first-child {
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-faint);
  width: 130px;
  padding-top: 13px;
  font-weight: 500;
}

.qce-card {
  background: linear-gradient(135deg, var(--blue-deep), var(--blue));
  color: white;
  padding: 24px;
  margin-top: 8px;
}
.qce-card h4 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  opacity: 0.7;
  margin-bottom: 8px;
}
.qce-card .qce-name {
  font-family: 'Source Serif 4', serif;
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}
.qce-card p { font-size: 14px; line-height: 1.55; opacity: 0.9; margin-bottom: 14px; }
.qce-card a { color: white; border-bottom: 1px solid rgba(255,255,255,0.4); font-size: 13px; font-family: 'JetBrains Mono', monospace; letter-spacing: 0.05em; }
.qce-card a:hover { border-bottom-color: white; }

/* ==================== FOOTER ==================== */
footer.site-footer {
  background: var(--blue-deep);
  color: rgba(255,255,255,0.75);
  padding: 36px 0 24px;
  margin-top: 60px;
}
.footer-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 32px;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
}
.footer-block h5 {
  font-family: 'JetBrains Mono', monospace;
  font-size: 10px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: white;
  font-weight: 500;
  margin-bottom: 12px;
}
.footer-block p, .footer-block a {
  display: block;
  font-size: 13px;
  line-height: 1.7;
  color: rgba(255,255,255,0.7);
  margin-bottom: 4px;
}
.footer-block a { border: none; }
.footer-block a:hover { color: white; }
.footer-block .brand-foot {
  font-family: 'Source Serif 4', serif;
  font-size: 22px;
  font-weight: 600;
  color: white;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}
.footer-block .brand-foot .si { color: var(--blue-bright); font-style: italic; }
.footer-bottom {
  max-width: 1200px;
  margin: 28px auto 0;
  padding: 18px 32px 0;
  border-top: 1px solid rgba(255,255,255,0.15);
  display: flex;
  justify-content: space-between;
  font-family: 'JetBrains Mono', monospace;
  font-size: 11px;
  letter-spacing: 0.05em;
  color: rgba(255,255,255,0.55);
}

/* ==================== RESPONSIVE ==================== */
@media (max-width: 1000px) {
  .masthead-inner { flex-wrap: wrap; }
  .masthead-right { border-left: none; padding-left: 0; text-align: left; }
  .hero-card { grid-template-columns: 1fr 1fr; }
  .about-layout { grid-template-columns: 1fr; }
  .cfp-grid { grid-template-columns: 1fr; gap: 0; }
  .attend-grid { grid-template-columns: 1fr; }
  .pc-card-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-inner { grid-template-columns: 1fr 1fr; gap: 28px; }
}

@media (max-width: 680px) {
  .topbar-inner { padding: 0 18px; flex-direction: column; gap: 4px; align-items: flex-start; }
  .masthead-inner { padding: 22px 18px 18px; gap: 16px; }
  .logo-mark { width: 56px; height: 56px; }
  .brand-title { font-size: 30px; }
  .nav-inner { padding: 0 8px; overflow-x: auto; flex-wrap: nowrap; }
  .nav-tabs { flex: 1; }
  .nav-btn { padding: 12px 14px; font-size: 13px; white-space: nowrap; }
  .qw-logo { width: 60px; height: 60px; }
  .tunneling-bridge { display: none; }
  .announce-inner { padding: 0 18px; flex-wrap: wrap; }
  .container { padding: 32px 18px 60px; }
  .page-title { font-size: 28px; }
  .hero-card { grid-template-columns: 1fr; gap: 18px; padding: 20px; }
  .topic-grid { grid-template-columns: 1fr; }
  .pc-card-grid, .pc-card-grid.cols-2 { grid-template-columns: 1fr; }
  .pc-list-grid { grid-template-columns: 1fr; }
  .session-header { flex-direction: column; gap: 4px; align-items: flex-start; }
  .stack-layer { grid-template-columns: 1fr; }
  .stack-layer .layer-name { border-right: none; border-bottom: 2px solid var(--blue-bright); padding: 10px 16px; }
  .footer-inner { grid-template-columns: 1fr; padding: 0 18px; }
  .footer-bottom { padding: 18px 18px 0; flex-direction: column; gap: 6px; }
  .banner-img { height: 180px; }
  .banner-img .caption { font-size: 17px; }
}

/* ==================== PC-CARD with photo + link (organizers and PC) ==================== */
.pc-card-link {
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}
.pc-card-link:hover {
  border-color: var(--blue-bright);
  box-shadow: 0 4px 14px rgba(30, 77, 140, 0.10);
  transform: translateY(-1px);
}
.pc-card-photo {
  width: 100%;
  aspect-ratio: 1 / 1;
  border-radius: 4px;
  overflow: hidden;
  background: var(--rule-soft);
  margin-bottom: 14px;
  border: 1px solid var(--rule);
}
.pc-card-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.pc-cards-compact .pc-card {
  padding: 14px;
}
.pc-cards-compact .pc-card-photo {
  margin-bottom: 10px;
}
.people-with-photos .pc-card .contact span {
  font-family: 'JetBrains Mono', monospace;
  font-size: 12px;
  color: var(--blue-bright);
  word-break: break-word;
}
.people-with-photos .pc-card .contact { margin-top: 8px; }
.people-with-photos.pc-card-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
@media (max-width: 480px) {
  .people-with-photos.pc-card-grid { grid-template-columns: 1fr 1fr; }
}